Assuming no injuries (and ignoring the real-world inevitability of fatigue), it is easy to imagine such a lineup doing reasonably well.

That is a side created entirely from Chelsea players currently out on loan at clubs around Europe. This month, when Bertrand made the temporary switch to Aston Villa for the remainder of the season, he became the 23rd individual to join that not-so-exclusive club, highlighting a trend at Stamford Bridge that is perhaps equal parts impressive and alarming.

David Ramos/Getty Images

Courtois and Lukaku, for example, would seem to have the quality to be a valuable addition to any top-flight squad, while Marin (25 in March) is the oldest of that group, underlining the likely long-term potential of a collection of players who all have received national recognition at either youth or senior level.

If we come to agree or estimate—or simply hazard a guess—that the aforementioned side would finish somewhere around 12th in the Premier League (it surely has the individual talent, especially in attack, to beat most of the league’s less-star studded squads on a given day, but perhaps lacks the physicality in defence to threaten the top 10 over a full season), it provokes meaningful questions.

Is the stockpiling of such talent really good for the players (many of whom see their careers lose momentum before their eyes), the club or the game as a whole?

And is this a case of the loan system being exploited and, if so, by whom?

THE HOLE AT THE HEART OF ENGLISH FOOTBALL

Alex Livesey/Getty Images

Many observers believe it is a clear exploitation of the loan system by Chelsea, one that should be addressed (i.e. stopped) by the powers-that-be as soon as possible.

But if the loan market is not currently in the midst of a revolution—although Chelsea’s situation is leading some to start calling for one—it is undoubtedly already undergoing something of an evolution.

Partly, this is a knock-on effect of the introduction of the Under-21 league in English football, replacing the old reserve system that traditionally provided fringe members of professional squads—the up-and-coming youngsters, the back-ups and unwanted senior pros—with their chance to play regular, semi-competitive games.

Designed in part to ensure young players greater exposure to a higher standard of football (the Under-21 league only allows three over-age players in each XI), it has inadvertently only further crystallised in the mind of some Premier League managers the difficult-to-bridge gap between Under-21 football and the demands of their division.

"The English setup, all the way to Under-19s, is one of the best development structures we have in the world," Everton manager Roberto Martinez recently told the podcast Followtonians, in a wide-ranging and thoughtful Q&A.

"Possibly the best. When they get from 19 to the first team [however], we are the worst, possibly.

"It is not competitive enough, the Under-21s is not a league that is going to develop players. So then you need to concentrate and send them out on loan."

Everton have high hopes for a number of youngsters—Hallam Hope, Conor Grant and goalkeeper Mason Springthorpe, to name just three. But the Under-21 league does not give them the necessary environment to prepare them to play for the first team, and thus all three have been loaned out this term to different levels of the English football pyramid in order to give them a taste of that experience.

Depending on how they fare, they may eventually return to the club’s Finch Farm training centre to greater first-team consideration.

For Everton, the system works both ways. While they loan out a lot of academy graduates, they are also able to welcome in talented prospects from other clubs.

That was the case of Gerard Deulofeu this summer, a player Barcelona were willing to send to Goodison Park as they believed Martinez’s style of play and regular cameos in English football would better prepare one of their most talented attacking starlets to make the huge jump from playing in Spain’s second tier to turning out for one of the very best sides in Europe.

On the loan market, Martinez adds:

It’s a big area for us. When you are developing a young player, there is a moment when that player has to move on because he is not ready for the first-team but he has done everything at the club internally. That happens to us.

Barcelona have exactly the same situation. Deulofeu scores 18 goals at Championship level, but he’s not ready for the first-team because he has someone called [Lionel] Messi ahead of him. What are you going to do with him?

Well, you are not going to send him anywhere—you need to send him somewhere where they play a similar way. As a football club we can give something that the player needs to learn.

We’ve had a few big clubs show an interest in sending us their youngsters. That’s only positive.

Chelsea, however, can relate to Barcelona’s situation more so than Everton’s. They only extremely rarely might take a player on loan (to cover a short-term gap in the squad or in advance of a permanent signing of said player) but have a constant stream of young players who are crying out for first-team experience (Lukaku, at Everton, being an obvious example); a need perhaps intensified by the fact the club have previously scoured Europe to recruit the most promising teenagers their scouts can uncover.

That is how they end up sending two starting XIs worth of players out to other clubs, even if, in all likelihood, many of them will never force their way back into the first-team reckoning.

Barcelona wanted Gerard Deulofeu to continue his development at EvertonClive Brunskill/Getty Images

Moses, Bertrand, Marin and even Lukaku (if reports are to be believed) face an uphill battle to change Jose Mourinho’s mind about them, while even players earlier in their development such as Chalobah, Traore and Omeruo only have a small window to impress before they risk becoming yesterday’s men in the club’s reckoning, brushed aside by the next crop of 18-22-year-olds with prodigious natural talents.

The question then is whether some of the club’s current loanees can avoid those obstacles and realise the potential often ascribed to them.

THE LOST GENERATION

Michael Regan/Getty Images

Almost ever since John Terry, the Blues have conspicuously struggled to produce homegrown talents who have gone on to become first-team regulars (Bertrand may have played in the 2012 Champions League final, but that was a rare appearance due to exceptional circumstances and his long-term future is far from assured).

Part of this is due to the constant managerial turnover; since Carlo Ancelotti—who briefly tried to blend the likes of Jeffrey Bruma, Josh McEachran and Patrick van Aanholt into the first-team setup—left in 2010, most Blues managers have lacked the job security and long-term remit to devote the sort of attention to the carefully planned and nuanced strategies required to slowly feed a prospect into a squad aiming to perform at the very highest level.

Josh McEachran's Chelsea career has stuttered to a haltScott Heavey/Getty Images

Producing your own players remains the cheapest way to build a squad, however, which is why Chelsea continue to snap up the best young talent they can find. This can be in England—for example, Chalobah, Nathan Ake, Isaiah Brown (who the club recently poached from West Brom)—but does not have to be, with the likes of Traore, Piazon and Wallace sourced (for varying fees) from all corners of the globe.

He left the club in 2010, but former Blues technical director Frank Arnesen perhaps summed up the club’s ongoing approach to the academy process when he told the Guardian:

A talent is a talent.

Not to be rude, but I have nothing to do with the English national team. They could win everything but if we lose I have a bad time. I am here for the fans of Chelsea, not for England.

But I do think it's important for the culture of the club that there are English players.

THE UNUSUAL PROVING GROUND

If there is a huge gap to overcome between the Under-21s and the first team, then in recent years Chelsea have often sent their players (English or foreign) to one particular destination in preparation for that challenge.

Vitesse Arnhem has always had links with English football—they began life as a cricket club and, like many clubs around Europe, their first manager was an Englishman—but it is now the only foreign-owned club in the Dutch top flight.

Currently, five Chelsea players are on loan at Vitas (known occasionally as "FC Hollywood on the Rhine"), with a further two (Gael Kakuta and Sam Hutchinson) having returned to London in January after disjointed spells.

Piazon, Van Aanholt, Christian Atsu and Cristian Cuevas have all helped the club to joint-top of the Eredivisie, with the January arrival of Bertrand Traore adding to the Blues contingent, as the Dutch club bid to spring a real surprise and defeat Ajax in the title race.

Dean Mouhtaropoulos/Getty Images

Vitesse have become a regular destination for Chelsea players since 2010 when Georgian businessman Merab Jordania bought the club. Even then, however, there was speculation that Jordania was simply acting as an intermediary for another investor—and in 2013 Russian billionaire Alexander Chigirinsky assumed full control of the club (Jordania remained as chairman).

Chigirinsky is known to be a friend and business associate of Roman Abramovich (they are both shareholders in Snegiri, the property developer), creating questions about the exact nature of the two clubs’ arrangement.

Are Chelsea loaning these players to Vitesse because Arnhem is a good, trusted place to continue their development—or is it simply a case of one billionaire doing a favour for another?

Chelsea Players on Loan at Vitesse, 2013-14

Player

Age

Position

Notes

Lucas Piazon

20

Forward

Regular starter

Christian Atsu

22

Attacking midfielder

Regular starter

Cristian Cuevas

18

Left-back/left wing

In reserve squad

Patrick van Aanholt

23

Left-back

Regular starter

Bertrand Traore

18

Midfielder

Squad player

Returned in January

Gael Kakuta

22

Forward

Squad player

Sam Hutchinson

24

Central defender

Went to regain fitness

B/R UK

If it is the latter, then the club’s current success provokes further thorny debates. If Vitesse go on to win the league, interrupting a Ajax-PSV-Feyenoord hegemony that is only breached once or twice a decade, will that be a worthy sporting achievement or simply a smaller club with unique and influential ties gaming the system?

The situation is certainly controversial in the Netherlands; especially as it is a footballing country that, with Ajax at the forefront, has increasingly come to pride itself on (and invest its identity in) an ability to produce and develop world-class players from the ages of seven or eight.

The technical director of Vitesse's local rivals NEC Nijmegen, Carlos Aalbers, suggested last year that a rule change might be necessary, as the flow of players from blue to yellow-and-black showed little signing of stopping.

"This is a new ­situation for us in Dutch football and it is worthy of discussion," Aalbers noted, per NBCSport. "It is six players on loan from Chelsea at Vitesse, but if this trend continues it could be nine or 10."

He then added: "[But] I want to be clear that I am not judging Vitesse or Chelsea because they are acting within the rules."

Chelsea’s own technical director, Michael Emenalo, subsequently deflected such comments by insisting to the Daily Express that the arrangement was about player development, not board-level handshakes and pacts:

For young players, the ages of 18 to 21 are the most difficult time. We felt it is better for them to go on loan to somewhere where they get good competition.

It’s working with Vitesse because the Dutch league plays in a desirable way and they have done what they promised. When they say they want a player, the player actually does play.

If tomorrow a Championship team in England wants the same kind of relationship with us it is no problem.

In fairness to Emenalo, since then both Chalobah and Omeruo have joined Middlesbrough on a temporary basis, while striker Patrick Bamford’s recent switch to Derby County (after an earlier spell at MK Dons) seems in part based on the belief that ex-England manager Steve McClaren will prove a good mentor.

Off the pitch, however, it is almost undeniable that Chelsea have a strong influence—with Blues board member (and long-time Abramovich aide) Marina Granovskaia reportedly helping the club with commercial deals, and another advisor, Piet de Visser, revealing the extent of his power after saying (per the Times) last year that he had recommended two potential new managers to the club and "I expect them to follow my advice."

The proof is in the pudding, however, and so far no Chelsea player has returned from a spell at Vitesse to graduate to the Chelsea first-team squad.

Ajax, and Dutch football in general, pride themselves in producing their own playersDean Mouhtaropoulos/Getty Images

Well, that is not strictly true—Nemanja Matic spent the 2010-11 season in Arnhem. Lest it be forgotten, however, that Chelsea gave up on him shortly after and sold him to Benfica as part of the David Luiz deal for a quoted fee of around £3m in 2011, buying him back this year for nearer £22m when the Serbian completed his development into the sort of combative, all-round midfielder they had initially hoped he would be.

The other prominent deal was in the opposite direction—Chelsea signed Vitesse product Marco van Ginkel for £8 million last summer. Van Ginkel made one start (in the Champions League loss to Basel) and two substitute Premier League appearances before tearing his ACL in a September Capital One Cup tie against Swindon.

Likened to Frank Lampard, it will be interesting to see how the 21-year-old is handled when he recovers from injury. Will he remain around the first-team squad, unlike so many of Chelsea’s players of his age, or—considering the arrival of Matic—will he be loaned out somewhere more likely to give him first-team football?

Will that be back to Vitesse?

WILL SOMEONE MAKE THE BREAKTHROUGH?

Nemanja Matic had to establish himself at Benfica before Chelsea re-signed himMike Hewitt/Getty Images

Of the five Chelsea players currently going through the Vitesse finishing school, Lucas Piazon is perhaps the best placed to make an imminent Chelsea impact. Comfortably among the top-three best players in the Eredivisie this season, per Whoscored.com’s Opta-powered metrics, the Brazilian (who recently turned 20) has been a key and consistent presence in his side’s title push with 11 goals and eight assists in just 17 appearances.

Whether he will get a chance at the club that bought him for an initial £5m in 2011 remains to be seen, however. The impending sale of Juan Mata to Manchester United slightly frees up the route to a place among Mourinho’s attacking three in his 4-2-3-1 setup (he has predominantly played on the left of a 4-3-3 this season, but he can play as a second striker or from the right), yet the club have already been linked with spending that Mata windfall on Basel’s Mohamed Salah and possibly also Inter’s Freddy Guarin.

Both players would further obstruct Piazon’s potential progress.

Back in October, Piazon acknowledged that he needed a "special" season to force his way into the Chelsea reckoning. Intriguingly, he also seemed to suggest that his parent club had coerced him in the direction Vitesse, with Liverpool (who would subsequently take Victor Moses) and Crystal Palace among those linked with a loan swoop.

The most important thing for me was to find somewhere to play a lot of games. My first hope was to stay in England and get some experience in the Premier League but Chelsea spoke to me and I came out here to see the club.

I liked the club and the city and the training ground. There are a lot of players from Chelsea and we have a good connection. We all want a future at Chelsea but it depends on us.

We are young and on loan and we have to do something special with our season to get back and stay at the club. We know if we don’t have a good season we will be back out on loan again.

This is the nature of top-level football. For young players, at some point it is their own talent, dedication and application that will decide what level they end up performing at. But, equally, the clubs have a responsibility to do their best to prepare and develop their youngsters, some of whom they have paid a lot to relocate from stable environments in their home countries.

B/R

Yet not all players develop at the same rate, regardless of whether they receive the highest possible coaching, which is partly why we so often hear about the "next big thing" who never made it, or why a player such as Diego Costa (another current Chelsea target) can suddenly establish himself as one of the world’s best only as he enters his mid-20s.

It is this inherent uncertainty to producing young players, along with the elite level of quality they require in their senior players, that will always inoculate Chelsea against accusations that they are failing their academy graduates, who often come to the club with the highest commendations but see others from their age group overtake them over time.

The haste with which Kakuta—who had expressed a belief he was stagnating after 18 months in Holland and is now likely to be sold at the first available opportunity—was recalled at the start of the month and Traore, who only officially signed on New Year's Day, was sent out to Vitesse in his stead may hint at an emotionless, cut-and-thrust side to Chelsea's approach, ditching players once their development stalls.

Equally, however, that conduct might underline their seriousness about trying to do the best for their players and the proactive way they go about that pursuit.

If the loan is not working, they nip it in the bud and give an opportunity to another. After years of helping its informal partner progress from being a lesser light in thier own domestic league, Vitesse are now perhaps just six months away from being a Champions League side.

Able to offer both a domestic title challenge and European action in a system that promotes attacking, technical football, suddenly Arnhem would appear to be the very stepping stone Martinez et al. are looking for with their youngsters.

It is perhaps just unfortunate, then, that some players have seen their own careers stunted (temporarily, or perhaps permanently) in helping build this vision. The likes of Matej Delac (2010-11), Slobodan Rajkovic (2010-11) and Tomas Kalas (2011-13) will almost certainly never become established stars at the club in whose pay they spent their formative years.

Then again, maybe they never had the talent or mentality for that, regardless of where they had gone out on loan.

And maybe it will be different for Piazon or Atsu or the next wave of Blues recruits told to go out and impress in Arnhem.